1. Field of the Invention
This invention relates to lasers of the type used in surgical procedures and, more particularly, to a holder for maintaining a laser fiber in a predetermined position relative to tissue to be laser treated.
2. Background Art
Endometrial laser ablation is now recognized as an alternative to treatment of certain uterine diseases by the performance of a hysterectomy. Among the many advantages of laser assisted surgery are the ability to precisely destroy localized areas of body tissue, excellent hemostasis, rapid healing of treated tissue with minimal discomfort to a patient, and reduced expense compared to similar procedures performed by alternative, conventional techniques.
Conventional laser surgery requires the use of a hysteroscope, which is a multi-purpose instrument that is inserted into a uterine cavity that has been previously distended with a fluid medium. The hysteroscope accommodates optical equipment and a laser fiber which is used to transmit laser energy to the endometrial tissues. The fluid medium serves multiple purposes In addition to distending the uterus, it cools the laser and can be used as a vehicle to carry away debris accumulated during the performance of a surgical procedure.
There are two generally recognized techniques for using lasers in surgical procedures--dragging and blanching. With the dragging technique, the laser fiber is drawn directly against and across tissue to be treated. In blanching, the emitting end of the laser fibers is maintained at a predetermined distance from a tissue and moved more slowly relative to the tissue than with the dragging technique to allow the treated tissue to change in color, in the case of an endometrial surface, from pink to white. More laser power is required in blanching procedures than in dragging procedures.
While laser surgery has been very successful, the performance thereof can be time consuming and occasionally hazardous to the patient when performed by conventional methods and employing conventional equipment. Lengthy operations can result in dangerous amounts of the distending fluid being absorbed into the body.
Constant observance of the location of the emitting end of the laser fiber is also required with conventional equipment to keep the laser fiber in a proper relationship with the tissue that is being treated thereby. Location of the emitting end of the laser too far away from the tissue can make it ineffective, whereas holding of the laser fiber too close to tissue may cause underlying tissue to be damaged and/or the laser fiber to be irreparably burned, which frequently results in a part of the fiber breaking off within a body cavity.
To observe the laser location during surgical procedures, optical instruments are introduced to the cavities in which the tissue is to be treated. The need for optical equipment complicates the surgical procedures by requiring additional space for the accommodation of optical fibers. Optical equipment is also difficult to use effectively within the body cavities. The fluid medium used to distend the cavity commonly becomes cloudy during the performance of surgical procedures. When this occurs, the procedure must be interrupted to allow the clouding to diminish.
Another problem with conventional procedures is that the emitting end of the laser fiber is frequently accidentally brought into contact with the tissue which it is treating during a blanching procedure. Because of the high power requirements for blanching, the emitting end of the laser can burn up and fall off after recurring contact with the tissue. The surgical procedure must then be interrupted to replace the fiber, refurbish it by polishing, and/or remove the broken off fragments of the fibers.
Another problem with conventional laser equipment is that it generally requires use by one with a high degree of skill.
A still further drawback with conventional techniques is that they may take a considerable period of time to perform. It is common to use a single laser fiber in conventional equipment. Consequently, the user thereof must make repeated passes of the laser over the tissue to be treated. This is time consuming and difficult to accomplish, and often undesirably results in certain tissue areas being repeatedly passed over by the laser beam.
A still further drawback with conventional laser structures is that they do not lend themselves to treatment of all surfaces on body cavities. In fact, certain of the body cavity surfaces may be entirely inaccessible to conventional laser equipment. One configuration of laser equipment is generally inadequate for treatment of all cavities contemplated to be treated by the laser. For example, certain surfaces in the uterus are in such a confined space that it is impossible to perform a blanching technique without the laser fiber contacting the endometrial tissues.